A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Tofranil Overdose, Contraindications and Information - Imipramine
Tofranil Overdose, Contraindications and Information - Imipramine
OVERDOSE
Children have been reported to be more sensitive
than adults to an acute overdosage of imipramine hydrochloride.
An acute
overdose of any amount
in infants or young children, especially, must be considered serious
and potentially fatal.
Signs and Symptoms
These may vary in severity depending upon factors such
as the amount of drug absorbed,
the age of the patient
and the interval between
drug ingestion and the start of treatment. Blood and urine
levels of imipramine may not reflect the severity of poisoning;
they have chiefly a qualitative rather than quantitative
value, and are unreliable indicators in the clinical management
of the patient.
CNS abnormalities may include drowsiness,
stupor, coma,
ataxia, restlessness,
agitation, hyperactive reflexes, muscle
rigidity, athetoid
and choreiform movements and convulsions. Cardiac abnormalities
may include arrhythmia, tachycardia, ECG
evidence of impaired
conduction and signs
of congestive failure.
Respiratory depression,
cyanosis, hypotension,
shock, vomiting, hyperpyrexia,
mydriasis and diaphoresis
may also be present.
Treatment
The recommended treatment
for overdosage with tricyclic antidepressants may change periodically.
Therefore, it is recommended that the physician contact a poison
control center
for current information
on treatment. Because CNS involvement, respiratory
depression and cardiac
arrhythmia can occur
suddenly, hospitalization
and close observation may be necessary, even when the amount ingested
is thought to be small or the initial
degree of intoxication
appears slight or moderate. All patients with ECG
abnormalities should have continuous cardiac
monitoring and be closely observed until well after cardiac
status has returned to
normal; relapses may occur after apparent recovery. In
the alert patient, empty
the stomach promptly
by lavage. In the obtunded
patient, secure the
airway with a cuffed
endotracheal tube before beginning lavage
(do not induce emesis). Instillation of activated charcoal slurry
may help reduce absorption
of imipramine.
Minimize external
stimulation to reduce
the tendency to convulsions. If anticonvulsants are necessary, diazepam
and phenytoin may
be useful. Maintain adequate respiratory
exchange. Do not use respiratory
stimulants.
Shock should be treated with supportive measures, such
as appropriate position, intravenous
fluids, and if necessary,
a vasopressor agent.
The use of corticosteroids in shock
is controversial and may be contraindicated in cases of overdosage
with tricyclic antidepressants. Digitalis may increase conduction
abnormalities and further irritate an already sensitized
myocardium. If congestive heart
failure necessitates
rapid digitalization,
particular care must be exercised.
Hyperpyrexia should be controlled by whatever external
means are available, including ice
packs and cooling sponge
baths, if necessary.
Hemodialysis, peritoneal
dialysis, exchange
transfusions and forced diuresis have been generally reported as
ineffective because of the rapid fixation of imipramine in tissues.
Blood and urine levels
of imipramine may not correlate with the degree
of intoxication, and are unreliable indicators in the clinical
management of the patient.
The slow intravenous
administration
of physostigmine salicylate
has been used as a last resort to reverse severe CNS
anticholinergic
manifestations of overdosage with tricyclic antidepressants; however,
it should not be used routinely, since it may induce seizures and
cholinergic crises.
CONTRAINDICATIONS
The concomitant
use of monoamine oxidase
inhibiting compounds is contraindicated. Hyperpyretic crises or
severe convulsive
seizures may occur in patients receiving such
combinations. The potentiation
of adverse effects can be serious or even fatal. When it is desired
to substitute imipramine
hydrochloride in patients receiving a monoamine
oxidase inhibitor,
as long an interval should elapse as the clinical
situation will
allow, with a minimum
of 14 days. Initial dosage
should be low and increases should be gradual and cautiously prescribed.
The drug is contraindicated
during the acute recovery
period after a myocardial
infarction. Patients with a known hypersensitivity
to this compound should not be given the drug. The possibility of
cross-sensitivity to other dibenzazepine compounds should be kept
in mind.
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